13.6% is the change from 581 to 660
Calculation steps:
[( 660 - 581 ) ÷ 581] x 100 = 13.6%
Formula
Percentage change = [(660 - 581) / 581] x 100
Subtract the new number by the original number
660 - 581 = 79
79 ÷ 581 = 0.1359724612736661
0.1359724612736661 x 100 = 13.6%